D'Alembert's equation and spherical functions

Functional equations in several variables: with applications to mathematics, information theory, and to the natural and social sciences

Choice Reviews Online · 1989 · 862 citations

Integral Geometry, Infinite Dimensional Analysis, Several Variables +13

The functional equation 𝑓(𝑥𝑦)+𝑓(𝑥𝑦⁻¹)=2𝑓(𝑥)𝑓(𝑦) for groups

Pl. Kannappan · Proceedings of the American Mathematical Society · 1968 · 105 citations · Full text

Functional Equation 𝑓, Ordered Group, Complex-valued Function +4

On certain related functional equations

W. Harold Wilson · Bulletin of the American Mathematical Society · 1920 · 89 citations · Full text

Function Theory, Generalized Function, Functional Analysis +1

Bounded K-spherical functions on Heisenberg groups

Chal Benson, Joe Jenkins, Gail Ratcliff · Journal of Functional Analysis · 1992 · 71 citations

Lie Group, Functional Analysis, K-spherical Functions +2

A class of symmetric and a class of Wiener group algebras

Jean Ludwig · Journal of Functional Analysis · 1979 · 62 citations

Spectral Theory, Lie Group, Representation Theory +5